Lake level is one of the most important lake characteristics which allows the results of different effects to be identified and detected. In this work time series of the water levels of Belorussian lakes were analysed in order to detect pattern variations, to evaluate quantitatively the transformation of the hydrological regime of lake ecosystems and to develop prediction models. The possibility of plotting predicting models of lake water levels one year in advance was shown. The complication in plotting predicting models is in its individuality, the huge volume of initial data and the impossibility of immediate assessment of the results. Additional complications are caused by the inhomogeneity of time series of water levels in lakes.
One of the soil fertility parameters is water content in the root zone; therefore the estimation of the transformation of water resources in mineral soils of Belarus is rather relevant. The analysis of plant available moisture content (PAMC) was conducted for the topsoil layer of 50 cm thickness for the period of monitoring from 1960 until 2001. Results were submitted as maps on the basis of which the spatial and time variability of the PAMC was estimated. The quantitative estimation of changes in the plant available moisture content was carried out with the help of gradients of linear trends